We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Enhancement of calcium oxide on hydrogen production and degradation of polylactic acid microplastics in anaerobic fermentation
AI summary Read the abstract
Polylactic acid (PLA) is promoted as an eco-friendly biodegradable plastic, but under conventional anaerobic conditions it degrades slowly and can accumulate as microplastics in sewage treatment systems. Adding calcium oxide (CaO) to anaerobic fermentation reactors both accelerated PLA microplastic degradation and boosted hydrogen gas production as an energy byproduct. The mechanism involves CaO creating mildly alkaline conditions that help break PLA's ester bonds while buffering against acid buildup that normally inhibits microbes. This suggests that chemical additives could make biological microplastic treatment more practical in wastewater settings while recovering renewable energy simultaneously.
Anaerobic fermentation provides a sustainable route for microplastic (MP) degradation with concurrent energy recovery. In this study, calcium oxide (CaO) was applied as a buffering agent to enhance hydrogen production and promote the degradation of polylactic acid (PLA) microplastics during anaerobic fermentation. Inocula from anaerobic and anoxic tanks were used to evaluate hydrogen production, metabolite transformation, and PLA degradation under varying CaO dosages. CaO addition significantly increased cumulative hydrogen yield and volatile fatty acid (VFA) production while accelerating lactic acid conversion. Mechanistically, CaO facilitated PLA degradation through weak-alkaline-assisted ester bond hydrolysis and mitigated excessive acidification by neutralizing accumulated VFAs, thereby stabilizing system pH. This buffering effect promoted the enrichment of hydrogen-producing and alkali-tolerant microorganisms and redirected metabolic pathways toward acetate-butyrate fermentation, collectively enhancing hydrogen production. At 2 g/L CaO, cumulative hydrogen yields increased by 78.52% and 50.56% in the anaerobic and anoxic systems, respectively, while PLA weight loss increased by 67.45% and 82.34%. These results demonstrate a synergistic chemical-biological mechanism by which CaO enhances microplastic degradation and biohydrogen recovery in anaerobic systems.
More Papers Like This
Polymer-specific effects of biodegradable plastic–derived microplastics on anaerobic digestion performance and microbial pathways
AI summary Read the abstract
Researchers systematically tested microplastics from eight biodegradable polymers in anaerobic digestion and found starkly different outcomes depending on polymer chemistry: PHB-derived particles actually boosted methane yields, while polylactic acid and cellulose diacetate severely inhibited the process, causing hydrogen buildup and prolonged lag phases.
The microbial response to biodegradable polylactic acid microplastics during anaerobic fermentation of waste activated sludge
AI summary Read the abstract
Polylactic acid (PLA) microplastics — often assumed to be benign because they are 'biodegradable' — were found to inhibit the breakdown of organic matter in wastewater sludge by 5–18%, disrupting microbial communities and key enzymes. The result challenges the assumption that biodegradable plastics are environmentally safe once they enter wastewater treatment systems.
Fate of polylactic acid microplastics during anaerobic digestion of kitchen waste: Insights on property changes, released dissolved organic matters, and biofilm formation
AI summary Read the abstract
Polylactic acid (PLA) microplastics were tracked through the anaerobic digestion of kitchen waste, revealing that PLA particles underwent surface changes and released dissolved organic matter but were not fully degraded during the process. The study shows that even supposedly biodegradable plastics can persist and alter biofilm formation in anaerobic digestion systems.
Polyethylene terephthalate microplastics affect hydrogen production from alkaline anaerobic fermentation of waste activated sludge through altering viability and activity of anaerobic microorganisms
AI summary Read the abstract
Polyethylene terephthalate (PET) microplastics were found to inhibit hydrogen gas production from anaerobic fermentation of waste sludge by reducing the viability and activity of hydrogen-producing microorganisms. This finding suggests that PET microplastics in wastewater treatment systems could interfere with biological processes used to recover energy and resources from sewage sludge.
The Hydrolytic Behavior of Poly(Lactic Acid)/Polystyrene‐ Grafted‐Hectorite Nanocomposite Films and Its Regulatory Mechanism on Microplastics
AI summary Read the abstract
Researchers tested how polylactic acid (PLA) films and PLA/hectorite nanocomposite films degrade in aqueous solutions of different pH levels. The nanocomposite films degraded more slowly and released fewer microplastic fragments than pure PLA, suggesting that clay mineral incorporation could reduce secondary microplastic generation from biodegradable plastics.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.